In general, an air conditioner for a vehicle is a device for cooling or heating the interior of a vehicle by cooling or heating while introducing outside air of the vehicle to the interior of the vehicle or circulating inside air of the vehicle. The air conditioner for the vehicle includes an evaporator disposed inside an air-conditioning case for a cooling action, a heater core for a heating action, and a mode converting door for selectively blowing the air cooled by the evaporator or the air heated by the heater core to each area of the vehicle.
Korean Patent No. 10-1151758 discloses a plate type heat exchanger. FIG. 1 is a perspective view of a water cooled heat exchanger according to a related art, and FIG. 2 is a schematic diagram showing a configuration of the water cooled heat exchanger according to the related art.
Referring to FIGS. 1 and 2, the conventional water cooled heat exchanger 9 includes a plurality of plates 1 stacked on one another, a refrigerant inlet 2 for introducing refrigerant therethrough, a refrigerant outlet 3 for discharging refrigerant therethrough, a coolant inlet 4 for introducing coolant therethrough, and a coolant outlet 5 for discharging coolant therethrough, which are disposed at one side thereof. The plates 1 are stacked on one another to form a refrigerant channel and a coolant channel therein.
The refrigerant flowing into the heat exchanger through refrigerant inlet 2 flows through the refrigerant channel formed by the plates 1 and is discharged out through the refrigerant outlet 3, so a refrigerant flow path 7 as illustrated in FIG. 2 is formed. Moreover, the coolant flowing into the heat exchanger through the coolant inlet 4 flows through the coolant channel formed by the plates 1 and is discharged out through the coolant outlet 5, so a coolant flow path 8 as illustrated in FIG. 2 is formed. The refrigerant of the refrigerant flow path 7 and the coolant of the coolant flow path 8 exchange heat with each other.
The conventional water cooled heat exchanger 9 performs heat exchange with refrigerant using waste heat of electronic unit coolant, which flowed various electronic units through the coolant flow path 8.
However, in case of an electric vehicle which generates lots of waste heat from coolant of a stack side, the conventional water cooled heat exchanger is disadvantageous in that it may not use the waste heat of the coolant of the stack side due to its structure that is not capable of exchanging heat between coolant and refrigerant of different kinds.
Moreover, in order to apply a structure capable of exchanging heat between coolant and refrigerant of different kinds, studies for providing an effective heat exchange ratio between coolant and refrigerant of different kinds are required.